Many kinds of removable couplings have an elastomeric seal assembly which is tightened to form a watertight seal against a pipe. It is noted that throughout the specification and claims, the term “pipe” encompasses any kind of generally cylindrical object. The coupling is generally a partial ring with clamping lugs or ears, which are drawn towards each other by means of one or bolts that are mounted on the ears or lugs. Tightening the bolt reduces the overall diameter of the coupling and thus causes the coupling to be tightened around the pipe and achieve the desired watertight seal. The lugs are generally at the top of the coupling—the 12 o'clock position.
It is important to form a uniformly tight seal around the entire circumference of the pipe. However, because such couplings are generally made of strong materials, such as steel, the area of the ears or lugs (which is less stiff than the rest of the coupling) is tightened more than the rest of the coupling, particularly 180° from the lugs (the 6 o'clock position). Even worse, the area of the ears or lugs can dig into the pipe due to the uneven tightening of the coupling. This can mar the pipe and also interfere with further tightening of the coupling.